Chemistry - CHEMICAL BONDING Question with Solution | TestHub

The molecular geometry of ${\mathrm{H}}_3{\mathrm{O}}^{+}$ is pyramidal. It consists of three hydrogen atoms bonded to the central oxygen atom, with one lone pair of electrons on the oxygen atom. 

The acetylide ion consists of two carbon atoms bonded together by a triple bond $(\mathrm{C}\equiv \mathrm{C})$ with a lone pair of electrons on the terminal carbon atom. So it is linear.

The${{\mathrm{NH}}_4}^{+ }$ion consists of a central nitrogen atom bonded to four hydrogen atoms. It is tetrahedral.

The ${\mathrm{ClO}}_2^{-}$ ion is bent in shape due to its molecular geometry. It consists of one central chlorine atom bonded to two oxygen atoms, with an additional lone pair of electrons on the central chlorine atom.

(A) ${\mathrm{H}}_3{\mathrm{O}}^{+}$ →         (III) Pyramidal

(B) Acetylide ion → (II) Linear

(C) ${\mathrm{NH}}_4^{+}$ ion →    (I) Tetrahedral

(D) ${\mathrm{ClO}}_2^{-}$ ion →    (IV) Bent